Abstract: In this paper, experimental testing and numerical analysis were used to investigate the effect of tube thickness on the face bending for concrete filled hollow sections connected to other structural members using Extended Hollobolts. Six samples were tested experimentally by applying pull-out load on the bolts. These samples were designed to fail by column face bending. The main variable in all tests is the column face thickness. Finite element analyses were also performed using ABAQUS 6.11 to extend the experimental results and to quantify the effect of column face thickness. Results show that, the column face thickness has a clear impact on the connection strength and stiffness. However, the amount of improvement in the connection stiffness by changing the column face thickness from 5mm to 6.3mm seems to be higher than that when increasing it from 6.3mm to 8mm. The displacement at which the bolts start pulling-out from their holes increased with the use of thinner column face due to the high flexibility of the section. At the ultimate strength, the yielding of the column face propagated to the column corner and there was no yielding in its walls. After the ultimate resistance is reached, the propagation of the yielding was mainly in the column face with a miner yielding in the walls.
Abstract: The increasingly sophisticated technologies have now been able to provide assistance for surgeons to improve surgical
performance through various training programs. Equally important to learning skills is the assessment method as it determines the learning and technical proficiency of a trainee. A consistent and
rigorous assessment system will ensure that trainees acquire the specific level of competency prior to certification. This paper
reviews the methods currently in use for assessment of surgical
skill and some modern techniques using computer-based
measurements and virtual reality systems for more quantitative
measurements
Abstract: In the paper the method of product analysis from
recycling point of view has been described. The analysis bases on set
of measures that assess a product from the point of view of final
stages of its lifecycle. It was assumed that such analysis will be
performed at the design phase – in order to conduct such analysis the
computer system that aids the designer during the design process has
been developed. The structure of the computer tool, based on agent
technology, and example results has been also included in the paper.
Abstract: Traveling salesman problem (TSP) is hard to resolve
when the number of cities and routes become large. The frequency
graph is constructed to tackle the problem. A frequency graph
maintains the topological relationships of the original weighted graph.
The numbers on the edges are the frequencies of the edges emulated
from the local optimal Hamiltonian paths. The simplest kind of local
optimal Hamiltonian paths are computed based on the four vertices
and three lines inequality. The search algorithm is given to find the
optimal Hamiltonian circuit based on the frequency graph. The
experiments show that the method can find the optimal Hamiltonian
circuit within several trials.
Abstract: An area-integrating method that uses the technique of total integrated light scatter for evaluating the root mean square height of the surface Sq has been presented in the paper. It is based on the measurement of the scatter power using a flat photodiode integrator rather than an optical sphere or a hemisphere. By this means, one can obtain much less expensive and smaller instruments than traditional ones. Thanks to this, they could find their application for surface control purposes, particularly in small and medium size enterprises. A description of the functioning of the measuring unit as well as the impact caused by different factors on its properties is presented first. Next, results of measurements of the Sq values performed for optical, silicon and metal samples have been shown. It has been also proven that they are in a good agreement with the results obtained using the Ulbricht sphere instrument.
Abstract: Rapid prototyping (RP) techniques are a group of
advanced manufacturing processes that can produce custom made
objects directly from computer data such as Computer Aided Design
(CAD), Computed Tomography (CT) and Magnetic Resonance
Imaging (MRI) data. Using RP fabrication techniques, constructs
with controllable and complex internal architecture with appropriate
mechanical properties can be achieved. One of the attractive and
promising utilization of RP techniques is related to tissue engineering
(TE) scaffold fabrication. Tissue engineering scaffold is a 3D
construction that acts as a template for tissue regeneration. Although
several conventional techniques such as solvent casting and gas
forming are utilized in scaffold fabrication; these processes show
poor interconnectivity and uncontrollable porosity of the produced
scaffolds. So, RP techniques become the best alternative fabrication
methods of TE scaffolds. This paper reviews the current state of the
art in the area of tissue engineering scaffolds fabrication using
advanced RP processes, as well as the current limitations and future
trends in scaffold fabrication RP techniques.
Abstract: The use of High Order Statistics (HOS) analysis is
expected to provide so many candidates of features that can be selected for pattern recognition. More candidates of the feature can
be extracted using simple manipulation through a specific mathematical function prior to the HOS analysis. Feature extraction
method using HOS analysis combined with Difference to the Nth-Power manipulation has been examined in application for Automatic
Modulation Recognition (AMR) to perform scheme recognition of three digital modulation signal, i.e. QPSK-16QAM-64QAM in the
AWGN transmission channel. The simulation results is reported
when the analysis of HOS up to order-12 and the manipulation of Difference to the Nth-Power up to N = 4. The obtained accuracy rate
of AMR using the method of Simple Decision obtained 90% in SNR > 10 dB in its classifier, while using the method of Voted Decision is
96% in SNR > 2 dB.
Abstract: The C3 plants are frequently suffering from exposure
to high temperature stress which limits the growth and yield of these
plants. This study seeks to clarify the physiological mechanisms of
heat tolerance in relation to oxidative stress in C3 species. Fifteen C3
species were exposed to prolonged moderately high temperature
stress 36/30°C for 40 days in a growth chamber. Chlorophyll
fluorescence (Fv/Fm) showed great difference among species at 40
days of the stress. The species showed decreases in Fv/Fm and
increases in malondialdehyde (MDA) content under stress condition
as well as negative correlation between Fv/Fm and MDA (r = -0.61*)
at 40 days of the stress. Hydrogen peroxide (H2O2) content before
and after stress in addition to its response under stress showed great
differences among species. The results suggest that the difference in
heat tolerance among C3 species is closely associated with the ability
to suppress oxidative damage but not with the content of reactive
oxygen species (ROS) which is regulated by complex network.
Abstract: A wide spectrum of systems require reliable
personal recognition schemes to either confirm or determine the
identity of an individual person. This paper considers multimodal
biometric system and their applicability to access control,
authentication and security applications. Strategies for feature
extraction and sensor fusion are considered and contrasted. Issues
related to performance assessment, deployment and standardization
are discussed. Finally future directions of biometric systems
development are discussed.
Abstract: Mechanical design of the thin-film solar framed
module and mounting system is important to enhance module
reliability and to increase areas of applications. The stress induced by
different mounting positions played a main role controlling the
stability of the whole mechanical structure. From the finite element
method, under the pressure from the back of module, the stress at Lc
(center point of the Long frame) increased and the stresses at Center,
Corner and Sc (center point of the Short frame) decreased while the
mounting position was away from the center of the module. In addition,
not only the stress of the glass but also the stress of the frame
decreased. Accordingly it was safer to mount in the position away
from the center of the module. The emphasis of designing frame
system of the module was on the upper support of the Short frame.
Strength of the overall structure and design of the corner were also
important due to the complexity of the stress in the Long frame.
Abstract: We present on the method of inverse coherence matrix for the estimation of network connectivity from multivariate time series of a complex system. In a model system of coupled chaotic oscillators, it is shown that the inverse coherence matrix defined as the inverse of cross coherence matrix is proportional to the network connectivity. Therefore the inverse coherence matrix could be used for the distinction between the directly connected links from indirectly connected links in a complex network. We compare the result of network estimation using the method of the inverse coherence matrix with the results obtained from the coherence matrix and the partial coherence matrix.
Abstract: To satisfy the need of outfield tests of star sensors, a
method is put forward to construct the reference attitude benchmark.
Firstly, its basic principle is introduced; Then, all the separate
conversion matrixes are deduced, which include: the conversion
matrix responsible for the transformation from the Earth Centered
Inertial frame i to the Earth-centered Earth-fixed frame w according to
the time of an atomic clock, the conversion matrix from frame w to the
geographic frame t, and the matrix from frame t to the platform frame
p, so the attitude matrix of the benchmark platform relative to the
frame i can be obtained using all the three matrixes as the
multiplicative factors; Next, the attitude matrix of the star sensor
relative to frame i is got when the mounting matrix from frame p to the
star sensor frame s is calibrated, and the reference attitude angles for
star sensor outfield tests can be calculated from the transformation
from frame i to frame s; Finally, the computer program is finished to
solve the reference attitudes, and the error curves are drawn about the
three axis attitude angles whose absolute maximum error is just 0.25ÔÇ│.
The analysis on each loop and the final simulating results manifest that
the method by precise timing to acquire the absolute reference attitude
is feasible for star sensor outfield tests.
Abstract: The photoluminescence (PL) at 1.55 μm from
semiconducting β-FeSi2 has attracted a noticeable interest for
silicon-based optoelectronic applications. Moreover, its high optical
absorption coefficient (higher than 105 cm-1 above 1.0 eV) allows this
semiconducting material to be used as photovoltanics devices.
A clear PL spectrum for β-FeSi2 was observed by Cu or Au coating
on Si(001). High-crystal-quality β-FeSi2 with a low-level nonradiative
center was formed on a Cu- or Au- reated Si layer. This method of
deposition can be applied to other materials requiring high crystal
quality.
Abstract: In recent years, rapid advances in software and hardware in the field of information technology along with a digital imaging revolution in the medical domain facilitate the generation and storage of large collections of images by hospitals and clinics. To search these large image collections effectively and efficiently poses significant technical challenges, and it raises the necessity of constructing intelligent retrieval systems. Content-based Image Retrieval (CBIR) consists of retrieving the most visually similar images to a given query image from a database of images[5]. Medical CBIR (content-based image retrieval) applications pose unique challenges but at the same time offer many new opportunities. On one hand, while one can easily understand news or sports videos, a medical image is often completely incomprehensible to untrained eyes.
Abstract: With the growth of modern civilization and
industrialization in worldwide, the demand for energy is increasing
day by day. Majority of the world-s energy needs are met through
fossil fuels and natural gas. As a result the amount of fossil fuels is
on diminishing from year to year. Since the fossil fuel is nonrenewable,
so fuel price is gouging as a consequence of spiraling
demand and diminishing supply. At present the power generation of
our country is mainly depends on imported fossil fuels. To reduce the
dependency on imported fuel, the use of renewable sources has
become more popular. In Bangladesh coconut is widely growing tree.
Especially in the southern part of the country a large area will be
found where coconut tree is considered as natural asset. So, our
endeavor was to use the coconut oil as a renewable and alternative
fuel. This article shows the prospect of coconut oil as a renewable
and alternative fuel of diesel fuel. Since diesel engine has a versatile
uses including small electricity generation, an experimental set up is
then made to study the performance of a small diesel engine using
different blends of bio diesel converted from coconut oil. It is found
that bio diesel has slightly different properties than diesel. With
biodiesel the engine is capable of running without difficulty.
Different blends of bio diesel (i.e. B80, B60, and B 50 etc.) have
been used to avoid complicated modification of the engine or the fuel
supply system. Finally, a comparison of engine performance for
different blends of biodiesel has been carried out to determine the
optimum blend for different operating conditions.
Abstract: Titanium oxide hollow microspheres were synthesized from organic precursor titanium tetraisopropoxide (TTIP) using continuous spray pyrolysis reactor. Effects of precursor concentration, applied voltage and annealing have been investigated. It was observed that the annealing of the as-synthesized TiO2 hollow microspheres at 2500C, which had an average external diameter of 200 nm, leads to an increase in the size and also more spherical shape. The precursor concentration was found to have a direct impact on the size of the microspheres, which is also evident in the absorption spectrum. The as-prepared TiO2 hollow microspheres exhibited good photocatalytic activity for the degradation of MO.
Abstract: The present work deals with the stabilisation of
organic clay using hydrated lime. Artificial organic clays were
prepared by adding kaolin and different humic acid contents. Results
given by physical testing show that the presence of humic acid has a
drawback effect on the untreated organic clay. The decrease in
specific gravity value was accompanied by a decrease in dry density
and plasticity of clay at higher humic acid contents. Significant
increase in shear strength at 7 days of curing period is observed in the
lime-treated samples up to 5% lime content. However shear strength
of lime-treated organic clay decreases at longer curing periods. The
results given by laboratory testing is further verified by
microstructure analysis. Based on the results obtained in this study, it
can be concluded that the presence of more than 1.5% humic acid
reduces significantly the efficiency of lime stabilization in organic
clays.
Abstract: A Vehicle-s door wireing harness arrangement structure is provided. In vehicle-s door wiring harness(W/H) system is more toward to arrange a passenger compartment than a hinge and a weatherstrip. This article gives some insight into the dimensioning process, with special focus on large deflection analysis of wiring harness(W/H) in vehicle-s door structures for durability problem. An Finite elements analysis for door wiring harness(W/H) are used for residual stresses and dimensional stability with bending flexible. Durability test data for slim test specimens were compared with the numerical predicted fatigue life for verification. The final lifing of the component combines the effects of these microstructural features with the complex stress state arising from the combined service loading and residual stresses.
Abstract: Biometrics methods include recognition techniques
such as fingerprint, iris, hand geometry, voice, face, ears and gait. The gait recognition approach has some advantages, for example it
does not need the prior concern of the observed subject and it can
record many biometric features in order to make deeper analysis, but
most of the research proposals use high computational cost. This
paper shows a gait recognition system with feature subtraction on a
bundle rectangle drawn over the observed person. Statistical results
within a database of 500 videos are shown.
Abstract: State-dependent Riccati equation based controllers are
becoming increasingly popular because of having attractive
properties like optimality, stability and robustness. This paper focuses
on the design of a roll autopilot for a fin stabilized and canard
controlled 122mm artillery rocket using state-dependent Riccati
equation technique. Initial spin is imparted to rocket during launch
and it quickly decays due to straight tail fins. After the spin phase, the
roll orientation of rocket is brought to zero with the canard deflection
commands generated by the roll autopilot. Roll autopilot has been
developed by considering uncoupled roll, pitch and yaw channels.
The canard actuator is modeled as a second-order nonlinear system.
Elements of the state weighing matrix for Riccati equation have been
chosen to be state dependent to exploit the design flexibility offered
by the Riccati equation technique. Simulation results under varying
conditions of flight demonstrate the wide operating range of the
proposed autopilot.